We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome,
Firefox,
Internet Explorer 11,
Safari. Thank you!

AR# 50678

13.x/14.x System Generator - Why does WaveScope block not show an unsigned signal as expected?

Description

Why do "unsigned" signals in the System Generator WaveScope block appear as "signed" even though the signals being viewed are output from blocks where they have been specifically set as "unsigned"?

For example, if I use a 6-bit unsigned counter, viewing this in the WaveScope showed a count from 0 to 31 continuing to -32 to 0, when it should be 0 to 63.

Solution

This is expected behavior. The WaveScope block defaults to show "Sign Magnitude" of signals, as a result, the WaveScope configuration also needs to be modified to show "unsigned" signals correctly.

Using the WaveScope Help, you will see a "Configuring the Signals' Presentation" section which describes how to open a SigConfig dialog box. This contains a "Sign-Magnitude" check box which is checked by default and this forces the signed behavior. Unchecking this allows the unsigned result to be displayed.